Answer: Unsupervised Learning

The correct answer is B) Unsupervised Learning. Unsupervised learning is used when you have input data without corresponding output labels, and the algorithm tries to find patterns or structures in the data on its own. This is different from supervised learning which requires labeled data, reinforcement learning which learns through rewards/punishments, and semi-supervised learning which uses a combination of labeled and unlabeled data.

Author: Ritesh Yadav